/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.
 * For example:Given the below binary tree and sum = 22,
 *            5
             / \
            4   8
           /   / \
          11  13  4
         /  \      \
        7    2      1
 * 
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
/**
 * @author Ivan
 *
 */
package problem112_Path_Sum;